Opposition Leader Tony Abbott is vowing to repeal the tax if he wins government.

Coalition senators argued fiercely against the tax during the final hours of debate in the Senate on Monday.

Queensland Liberal senator Sue Boyce said the government's tax was an attack on the mining industry and another example of the union-dominated party slugging profitable companies.

"They are singing the song of the politics of envy, non-stop," she told Senate.

"The introduction of the market valuation scheme to calculate applicable deductions gives the big three companies a significant tax shield that is not available to small and mid-tier mining companies."

But Labor senator Glenn Sterle hit back calling for the opposition to detail where and how many jobs would be affected by the mining industry once the tax threshold of the impost was reached.

"Bring a miner in here, challenge me, bash me around the ears and tell me one mine that is going to put off workers because all of a sudden they've cracked the $75 million profit and they are paying a little bit of tax," Senator Sterle said.

"Rio Tinto, BHP and Xstrata are the major employers in the mining industry," he added, referring the billion dollar profits generated by the three.

Planned capital investment in mining is estimated at $119.8 billion in the year to end-June 2013 - which covers the first 12 months of the mining tax due to be implemented on July 1, 2012.

The Australian Greens made a last ditch bid on Monday night to have the tax rate increased to 40 per cent but that amendment was defeated.

Another Greens amendment to apply the tax to gold, uranium and rare earth minerals was ruled out of order by Senate President John Hogg and thrown out.

Liberal Senator Mathias Cormann also failed in his attempt get the government to release estimates and assumptions about the mining tax.